In most of regions of China, it was cold in winter. Thus, especially in Yunnan province, Guizhou province, Sichuan province, Hubei province and Hunan province, a pavement is easy to ice in winter, affecting the anti-skid capability of the pavement, reducing traffic capacity, increasing a potential risk of traffic accidents, even causing traffic to be blocked in severe cases, and bringing about frightful troubles for normal travel of people and disturbance of normal living state of people. For the purpose of anti-skid effect, a conventional method involves spreading snow-melting agents for removal of snow and ice. Although it is capable of temporarily mitigating traffic and improving driving safety, it causes severe destruction and contamination on roadways and structures thereof, and surrounding environment such as soil and water bodies. If an anti-icing material which can actively inhibit icing on the pavement is developed, it would bring about favorable economic and social benefits in view of preventing roadway icing and enhancement of driving safety in winter.
With respect to chemical anti-icing materials for inhibition of pavement icing, as early as 1960s, an anti-icing salt called Verglimit was invented in Switzerland. Verglimit is a solid composite pavement anti-icing material derived by chemical processing of calcium chloride as a main ingredient, a small amount of sodium chloride and sodium hydroxide as an accessory ingredient, with linseed oil. The pavement anti-icing material was used in some trial pavements both in China and abroad, and had a certain anti-icing and anti-skid effect, but failed to be promoted in a large scale as a result of deficiencies. U.S. Pat. No. 6,982,044 discloses a method for encapsulating chlorate surface with thermo-sensitive phenolic resin. German Patent No. DE-OS 2426200, discloses a preparation method for modification of chloride with polyvinyl acetate, polyvinyl alcohol, epoxy or acrylic resins. In the foregoing patents, corrosion of steel bars by chloride ion was inevitable, and research on slow release materials was not disclosed. Accordingly, it is significant in economy to develop a slow release anti-icing material for the bituminous pavement having a relatively simple process for preparation and a low price without corroding the steel bars.